Right whales were first classified in the Balaena genus in 1758 by Carl Linnaeus, who at the time considered all right whales (including the bowhead) to be a single species. Through the 1800s and 1900s, in fact, the family Balaenidae has been the subject of great taxonometric debate. Authorities have repeatedly recategorized the three populations of right whale plus the bowhead whale, as one, two, three or four species, either in a single genus or in two separate genera. In the early whaling days, they were all thought to be a single species, Balaena mysticetus.[4]

The southern right whale was initially described as Balaena australis by Desmoulins in 1822. Eventually, it was recognized that bowheads and right whales were in fact different, and John Edward Gray proposed the Eubalaena genus for the right whale in 1864. Later, morphological factors such as differences in the skull shape of northern and southern right whales indicated at least two species of right whale—one in the Northern Hemisphere, the other in the Southern Ocean.[4] As recently as 1998, Rice, in his comprehensive and otherwise authoritative classification, Marine mammals of the world: systematics and distribution, listed just two species: Balaena glacialis (all of the right whales) and Balaena mysticetus (the bowheads).[5]

In 2000, Rosenbaum et al. disagreed, based on data from their genetic study of DNA samples from each of the whale populations. Genetic evidence now clearly demonstrates that the northern and southern populations of right whale have not interbred for between 3 million and 12 million years, confirming the southern right whale as a distinct species. The northern Pacific and Atlantic populations are also distinct, with the North Pacific right whale being more closely related to the southern right whale than to the North Atlantic right whale.[6] Genetic differences between E. japonica (north pacific) and E. australis (south pacific) are much smaller than other baleen whales represent among different ocean basins.[7]

It is believed that the right whale populations first split because of the joining of North and South America. The rising temperatures at the equator then created a second split, into the northern and southern groups, preventing them from interbreeding.[8]

In 2002, the Scientific Committee of the International Whaling Commission (IWC) accepted Rosenbaum's findings, and recommended that the Eubalaena nomenclature be retained for this genus.[9]

The cladogram is a tool for visualizing and comparing the evolutionary relationships between taxa. The point where a node branches off is analogous to an evolutionary branching – the diagram can be read left-to-right, much like a timeline. The following cladogram of the family Balaenidae serves to illustrate the current scientific consensus as to the relationships between the southern right whale and the other members of its family.

Like other right whales, the southern right whale is readily distinguished from others by the callosities on its head, a broad back without a dorsal fin, and a long arching mouth that begins above the eye. Its skin is very dark grey or black, occasionally with some white patches on the belly. The right whale's callosities appear white due to large colonies of cyamids (whale lice). It is almost indistinguishable from the closely related North Atlantic and the North Pacific right whales, displaying only minor skull differences. It may have fewer callosities on its head than North Atlantic and more on its lower lips than the two northern species.[4][10] Biological functions of callosities are unclear although the primal role has been considered to be for protection against predators, and whales' declines may affect on diversities and quantities of barnacles.[11]

An adult female is 15 m (49 ft)[12] and can weigh up to 47 tonnes (46 long tons; 52 short tons),[12] with the larger records of 17.5–18 m (57–59 ft)[13][14] in length and 80 tonnes (79 long tons; 88 short tons)[15] or up to 90 tonnes (89 long tons; 99 short tons) in weight,[16] making them slightly smaller than other right whales in the Northern Hemisphere.[17] The testicles of right whales are likely to be the largest of any animal, each weighing around 500 kg (1,100 lb). This suggests that sperm competition is important in the mating process.[18]

Right whales do not normally cross the warm equatorial waters to connect with the other species and (inter)breed: their thick layers of insulating blubber make it difficult for them to dissipate their internal body heat in tropical waters. However, based on historical records and unconfirmed sightings in modern periods, E. australis transits may indeed occur through equatorial waters.[19] Moreover, a stranding of a 21.3 m (71 feet) long right whale at Gajana, northwestern India in November, 1944 was reported, however, true identity of this animal is unclear.[20][21]

The proportion and numbers of molten-coloured individuals are notable in this species compared with the other species in the Northern Hemisphere. Some whales remain white even after growing up.[22]

Life span is not clear although whales seem to reach over 100 years old.[23]

Like other right whales, they are rather active on the water surface, and curious towards human vessels. Southern rights appear to be more active and tend to interact with humans more than the other two northern species.[citation needed] One behavior unique to the southern right whale, known as tail sailing, is that of using their elevated flukes to catch the wind, remaining in the same position for considerable amount of time. It appears to be a form of play and is most commonly seen off the coast of Argentina and South Africa.[10] Some other species such as humpback whales are also known to display. Right whales are often seen interacting with other cetaceans, especially humpback whales[24] and dolphins. There have been records of southern rights and humpbacks thought to be involved in mating activities off Mozambique,[25] and along Bahia, Brazil.[26]

They have very strong maternal connections with locations and gene pools they were born in,[27][28] and especially males may follow patterned migration routes.[29] Calving females are known to return to their 'birth spots' at 3-years intervals[30] as the most commonly seen calving intervals are 3 years which may vary from 2 up to 21 years due to multiple factors.[31][32] Specific congregation areas in the same region may function as for different objectives for whales.[33]

This species has been recognized to nurse unrelated orphans on occasions.[34]

The southern right whale spends summer in the far Southern Ocean feeding, probably close to Antarctica. If the opportunity arises, feeding can occur even in temperate waters such as along Buenos Aires.[35][36] It migrates north in winter for breeding and can be seen by the coasts of Argentina, Australia, Brazil, Chile, Namibia, Mozambique, Peru, Tristan de Cunha, Uruguay, Madagascar, New Zealand and South Africa, however, whales have been known to winter on sub-Antarctic regions.[37][38] The total population is estimated to be around 10,000. Since hunting ceased, stocks are estimated to have grown by 7% a year. It appears that the South American, South African and Australasian groups intermix very little if at all, because maternal fidelity to feeding and calving habitats is very strong. The mother also passes these choices to her calves.[39]

Whaling records among the hemisphere including a certain whaling ground in central northern Indian Ocean[40] and recent sightings among near-equatorial regions have occurred, and if the later mentioned sighting off Kiribati was truly of E. australis, this species could cross the Equator on irregular occasions and their original distributions might have been much broader and more northerly distributed than that of the present status.[19][41] As above mentioned, there was one record of a "right whale" stranded at northwestern coast of continental India.

Other than sheltered and calm waters, calving grounds have been identified close to high wave coastal areas, vicinity to land cliffs and deep waters where sounds of waves may prevent predators' acoustics searches for infants and calving cows, and deep areas close to shallows may function as training grounds for calves to prepare for upcoming migrations to feeding grounds.[42]

The most recent population estimates, published by National Geographic in October 2008, put the southern whale population at 10,000. An estimate of 7,000 followed a March 1998 IWC workshop. Researchers used data about adult female populations from three surveys (one in each of Argentina, South Africa and Australia, collected during the 1990s) and extrapolated to include unsurveyed areas, number of males and calves using available male:female and adult:calf ratios to give an estimated 1999 figure of 7,500 animals.[43]

Aside from impacts on whales and environments caused by mankind, their distributions and residences could be largely effected by presences of natural predators or enemies,[37] and similar trends are also expectable for other subspecies.[44]

Hermanus in South Africa has become known as a mecca for whale watching, during the Southern Hemisphere winter months (June – October) the southern right whales migrate to the coastal waters of South Africa, with in excess of 100 whales known to be in the Hermanus area. Whilst in the area, the whales can be seen with their young as they come to Walker Bay to calve and mate. Many behaviours such as breaching, sailing, lobtailing, or spyhopping can be witnessed. In False Bay whales can be seen from the shore from July to October while both Plettenberg Bay and Algoa Bay are also home to the southern right whales from July to December. They can be viewed from land as well as by boat with licensed operators conducting ocean safaris throughout the year.

Recent increases in numbers of whales visiting the north-eastern part of South Africa, the so-called Dolphin Coast such as around Ballito[46] and off Umdloti Beach,[47] indicates the whales' normal ranges are expanding and that re-colonising historical habitats will likely continue as more whales migrate further north.

In Namibia, the majority of confirmed whales are restricted to the south of Luderitz, the southern edge of the country, and only a handful of animals, but with good increases in numbers, venture further north to historical breeding grounds such as at Walvis Bay. Until hunting, including illegal mass operations by Soviet Union ceased, whales had been rare along Namibian shores as no sighting records north of Orange River until 1971,[48] and the first calving activities were confirmed as late as the 1980s.[49]

Due to illegal whaling by the Soviet Union, the recovery of many stocks including the population off Tristan da Cunha[68] and adjacent areas such as Gough Island had been severely hindered, resulting in relatively few numbers of visiting animals.

Based on capture records, whales once reached to the island of Saint Helena as well.[41]

In Uruguay, coastal areas such as Punta del Este host congregating sites for whales in breeding seasons, but not likely as calving grounds.[101] Their recovery helped create a whale-sanctuary off Latin America;[102] the creation of this protected area had been prevented for nearly a decade by pro-whaling nations such as Japan.

For the critically endangered Chile/Peru population, the Cetacean Conservation Center (CCC) has been working on a separate program for right whales. This population, containing no more than 50 or less individuals, is under threats of increasing ship lanes and fishing industries.[103] 124 sightings in total had been recorded during 1964–2008 period.[104] Aside from vagrants' records, Peru's coastlines possibly host one of the northernmost confirmed range of the species along with Gabon,[19]Senegal, Tanzania, Brazilian coasts, Madagascar, Indian Ocean, western Australia, Kermadec Islands, and tropical waters including South Pacific Islands.[19] The Alfaguara project targeting cetaceans in Chiloe[105][106] may possibly target this species as well in the future since calving activities have been confirmed in Chiloé Archipelago.[107] Foraging grounds of this population is currently undetected, but possibly Chiloé and down south of Caleta Zorra to southern fiords such as from Penas Gulf to Beagle Channel although numbers of confirmations are small in the Beagle Channel. .[108] Some hopes arising for establishment of new tourism industry in eastern side of the Strait of Magellan[109] most notably in the vicinity of Cape Virgenes[110] and Punta Dungeness as the number of sightings increases.[111][112][113] It is unknown whether these increases are due to re-colonisation by whales from the Patagonian population.

Occurrences of brindle individuals have been confirmed from this population as well.[114][115]

Historically, populations in Oceanian regions had been very robust.[41] There were stories of early settlers complaining that sounds of cavorting whales kept them awake at night in various locations such as on Wellington Bay and River Derwent. Satellite tracking conducted suggests that there are at least some interactions between populations in these two nations,[116][117] but the extent thereof is unknown. Furthermore, historical distributions of New Zealand and southeast or east Australian groups have been speculated to share at least calving grounds, and significant losses of local calving grounds may provide habitats to different groups.[118]

Southern right whales in Australian waters show higher rate of recoveries, as have increased from 2,100 whales in 2008[119] to 3,500 individuals in 2010.[30] Two genetically distinct groups inhabit Australian waters; the southwestern population of 2,900 whales in 2012 currently holding majority of whole Australian population and critically endangered southeastern group counting only dozens to 300 individuals.

Right whales can be found in many parts of southern Australia, where the largest population is found at the Head of the Bight in South Australia, a sparsely populated area south of the middle of the Nullarbor Plain. Over 100[120] individuals are seen there annually from June to October. Visitors can view the whales from cliff-top boardwalks and lookouts, with whales swimming almost directly below. A more accessible South Australian location for viewing whales is Encounter Bay where the whales can be seen just off the beaches of the Fleurieu Peninsula, centred around the surfing town of Middleton. A newer nursery ground has been established on Eyre Peninsula, especially at Fowlers Bay. Numbers are much smaller at these locations compared to the Bight, with an average of a couple of whales per day, but in recent years there have been regular sightings of more than ten whales at a time off Basham Beach, near Middleton.[121] The South Australian Whale Centre at Victor Harbor has information on the history of whaling and whale watching in the area, and maintains an on-line database of whale sightings.[122] Whale numbers are scarcer in Victoria where the only established breeding ground which whales use each year, in very small numbers, is at Warrnambool. However, as the whales do seem to be increasing in number generally, but not showing any dramatic increases at Warrnambool, they may be extending their wintering habitats into other areas of Victoria, where the numbers of sightings are slowly increasing. These areas include around Melbourne, such as in Port Phillip Bay, along Waratah Bay, at Ocean Grove, Warrnambool, on Mornington Peninsula, in Apollo Bay, and on Gippsland coasts and at Wilsons Promontory. Tasmania is another, newer, wintering ground showing dramatic increases in recent years. The waters off the Western Australia, New South Wales, and Queensland coasts had previously been inhabited by whales. Their historical range was much wider and was spread around the southern coast of the continent, extending up to Australian Abrolhos Island,[123]Exmouth and Shark Bay on the west coast, and to Hervey Bay and Moreton Bay to Great Barrier Reef[124] or further north on the east coast. The east coast population is still endangered and very small (in low-tens),[125] contributing in small numbers and limited re-colonization, but increases have been confirmed in many areas such as the vicinity of Port Jackson, Port Stephens, Twofold Bay, Jervis Bay, Broulee,[126]Moruya River,[127][128]Narooma,[129]Byron Bay,[130] and so on, and there have been 12 foraging areas officially announced.[131]

Many features are still unknown about current right whale population(s) in New Zealand waters. However, studies by the Department of Conservation and sightings reported by locals helped to deepen understanding.[134] Pre-exploitation size of New Zealand group could have been up from 28,800 to 47,100 in total where 35,000 to 41,000 catches were made between 1827 and 1980. The number of whales survived commercial and illegal whaling operations might be decreased to as few as 30 whales.[118][135] Not a single sighting or stranding was recorded between 1928 and 1963 on main islands, and full recovery is estimated to take about 60 years. As below mentioned, if illegal mass operations by Soviet with supports from Japan taken 372 whales in 1960s[136] had not been taken place, New Zealand population could have been three or four times larger than the current size.[137]

The population at the sub-Antarctic Auckland Islands is showing a remarkable recovery but with the lowest genetic diversities in the world,[138] while the recovery state in Campbell Islands is slower,[38] and possible number of whales after the World War 2 could have been fewer than 20 individuals in total.[116] Right whales had not been confirmed on main islands for 36 years until 1963 when 4 separate sightings including a cow-calf pair were made among wide range, and remnants of sub-Antarctic populations were re-discovered in 1990s as opportunistic sightings had been reported in 1980s.[116]

Today, the majority of right whales congregate at Auckland and Campbell Islands and forming exceptionally dense and limited congregations including all the sex groups such as mating adults and calving females within and adjacent to Port Ross,[139] where up to 200 whales may winter at the same time.[140] It is notable that whales, including all the age groups[141] are present in this small area annually, not only as feeding and summering[142] grounds but also mainly for wintering, breeding, and calving during harsh, cold periods. Low genetic diversities due to whaling pressures caused changes in skin colorations on this group as well.[138] Scientists used to believe there was a very small remnant population of southern right whales inhabiting New Zealand's main islands (North and South Island), containing probably 11 reproductive females.[143] In winter, whales migrate north to New Zealand waters and large concentrations occasionally visit the southern coasts of South Island. Bay areas along Foveaux Strait from Fiordland region to northern Otago are important breeding habitats for right whales, especially Preservation[144] and Chalky Inlets,[145]Te Waewae Bay,[146] and Otago Peninsula.[147][148] Calving activities are observed all around the nation, but with more regularity around North Island shores from the Taranaki coast in the west to Hawke's Bay, Bay of Plenty in the east, and areas in Hauraki Gulf such as Firth of Thames or Bay of Islands in the north.

Recent study revealed that the right whale populations from New Zealand's main islands and the sub-Antarctic islands interbreed, though it is still unknown whether the two stock originally came from a single population.[154] Feeding areas in pelagic waters are rather unclear while congregations have been confirmed along southern edge of the Chatham Rise.[155]

It is unclear whether (part of) whales found either historically or currently on areas within Australian ranges that are located close to the ranges of New Zealand whales such as Norfolk Island and Macquarie Island, do or do not originate in New Zealand group(s).

In oceanic islands and offshore waters other than the above-mentioned areas, very little about the presence and recovery status of southern right whales is known. Right whales' historical ranges were much greater than today as whales were known to occur in lower latitude areas such as around Pacific Islands during the whaling era such as catches off Kiribati,[156] and also frequented lower latitudes of the central Indian Ocean.

Catches had occurred on central Indian Ocean near the Equator, especially around the area between Diego Garcia, Egmont Islands, and Great Chagos Bank in west, and Cocos (Keeling) Islands in east, being comparable to the range of some other stocks among Latin America, Africa, and south Pacific islands including Kiribati, the northernmost occurrences of all the populations known today.[40]

By 1750 the North Atlantic right whale was as good as extinct for commercial purposes and the Yankee whalers moved into the South Atlantic before the end of the 18th century. The southernmost Brazilian whaling station was established in 1796, in Imbituba. Over the next one hundred years, Yankee whaling spread into the Southern and Pacific Oceans, where the American fleet was joined by fleets from several European nations.

The southern right whale had been coming to New Zealand waters in large numbers before the 19th century, but was extensively hunted from 1830–1850. Hunting gradually declined with the whale population and then all but ended in coastal New Zealand waters.[165] The beginning of the 20th century brought industrial whaling, and the catch grew rapidly. By 1937, according to whalers' records, 38,000 were captured in the South Atlantic, 39,000 in the South Pacific, and 1,300 in the Indian Ocean. Given the incompleteness of these records, the total take was somewhat higher.[166]

As it became clear that stocks were nearly depleted, right whaling was banned in 1937. The ban was largely successful, although some illegal whaling continued for several decades. Madeira took its last two right whales in 1968. Illegal whaling continued off the coast of Brazil for many years and the Imbituba station processed right whales until 1973. The Soviet Union admitted illegally taking over 3,300 during the 1950s and 1960s,[167] although it only reported taking 4.[168] Illegal operations continued even in 70s, such as the case in Brazil until 1973.[13] It was also revealed that Japan was supporting these destructive hunts by neglecting and disregarding monitoring obligations. Furthermore, there were agreements between Japan and the Soviet Union to keep their illegal mass whaling activities in foreign/international protected waters in confidence.[169]

Whales began to be seen again in Australian and New Zealand waters from the early 1960s.[165] It is claimed that if the illegal hunts by the Soviet Union had never happened, the New Zealand population would be three or four times larger than its current size.[137]

The southern right whale, listed as "endangered" by CITES, is protected by all countries with known breeding populations (Argentina, Australia, Brazil, Chile, New Zealand, South Africa and Uruguay). In Brazil, a federal Environmental Protection Area encompassing some 1,560 km2 (600 sq mi) and 130 km (81 mi) of coastline in Santa Catarina State was established in 2000 to protect the species' main breeding grounds in Brazil and promote regulated whale watching.[170] The southern right whale is listed on Appendix I[171] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) as this species has been categorized as being in danger of extinction throughout all or a significant proportion of their range. This species is also covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MoU).[172]

One possibly significant contributor to the calf mortality rate has alarmed scientists – since at least 1996, kelp gulls off the coast of Patagonia have been observed attacking and feeding on live right whales.[174] The kelp gull uses its powerful beak to peck down several centimetres into the skin and blubber, often leaving the whales with large open sores – some of which have been observed to be half a meter in diameter. This predatory behavior, primarily targeted towards mother/calf pairs, has been continually documented in Argentinian waters, and continues today. Observers note that the whales are spending up to a third of their time and energy performing evasive maneuvers – therefore, mothers spend less time nursing, and the calves are thinner and weaker as a result. Researchers speculate that many years ago, waste from fish processing plants allowed the gull populations to soar. Their resulting overpopulation, combined with reduced waste output, caused the gulls to seek out this alternative food source.[175] Scientists fear that the gulls' learned behaviour could proliferate, and the IWC Scientific Committee has urged Brazil to consider taking immediate action if and when similar gull behaviour is observed in their waters. Such action may include the removal of attacking gulls, following Argentina's lead in attempting to reverse the trend.[90]

The southern right whale has made Hermanus, South Africa one of the world centers for whale watching. During the winter months (June to October), southern right whales come so close to the shoreline that visitors can watch them from the shore as well as from strategically placed hotels. Hermanus also has two boat–based whale watching operators. The town employs a "whale crier" (cf.town crier) to walk through the town announcing where whales have been seen. Southern right whales can also be watched at other winter breeding grounds. In False Bay whale-watching can be done from the shore or from the boats of licensed operators in Simon's Town. Plettenberg Bay along the Garden Route of South Africa is another mecca for whale watching not only for southern rights (July to December)but throughout the year. There are both land based and ocean safaris boat based whale encounters on offer in this beautiful town. Southern right whales can also be seen off the coast of Port Elizabeth with marine eco tours running from the Port Elizabeth harbour, as some southern right whales make Algoa Bay their home for the winter months.

Whales are occasionally observed during tours in Namibia, Mozambique and Madagascar, where sighting rates along Namibian coasts shows dramatic increases in the recent years.

In Brazil, Imbituba in Santa Catarina has been recognized as the National Right Whale Capital and holds annual Right Whale Week celebrations in September, when mothers and calves are more often seen. The old whaling station there is now a museum that documents the history of right whales in Brazil. In Argentina, Península Valdés in Patagonia hosts (in winter) the largest breeding population, with more than 2,000 catalogued by the Whale Conservation Institute and Ocean Alliance.[176] As in the south of Argentina, the whales come within 200 m (660 ft) of the main beach in the city of Puerto Madryn and form a part of the large ecotourism industry. Uruguay's Parliament on 4 September 2013, has become the first country in the world to make all of its territorial waters a safehaven for whales and dolphins. Every year, dozens of whales are sighted, especially in the departments of Maldonado and Rocha during the months of winter.[177] Swimming activities for commercial objectives had been banned in the area in 1985,[178] but is legalized in Gulf of San Matías where this is the only location in the world for tourists to be permissioned to swim with the species.[179] Land-based watching and occasional kayaking with whales activities are Various other locations where is not renown for whale-watching industries as much as Puerto Madryn and with less restrictions on approaching whales, such as at Puerto Deseado,[180][181][182] Mar del Plata,[183][184] and Miramar in Buenos Aires.[185][186][187][188]

Though their numbers are dangerously small, land-based sightings of whales are on the increase in recent years off Chile and Peru, with some hope of creating new tourism industries,[189] especially in the Strait of Magellan, most notably around Cape Virgenes.[112]

In Australia's winter and spring, southern right whales can be seen from the Bunda Cliffs and Twin Rocks, both along the remote Great Australian Bight in South Australia.[10] In Warrnambool, Victoria, a right whale nursery is popular with tourists in the winter and spring. Their normal range is extending with the species recovering and re-colonizing other areas of the continent, especially around coastal waters of New South Wales and Tasmania. In Tasmania, the first birth since the 19th century was recorded in 2010 in the River Derwent.

Similarly, southern right whales may provide chances for the public to observe whales from shore on New Zealand's coasts with greater regularity than in the past, especially in southern Fiordland, Southland through to the Otago coast,[190] and on the North Island coast, especially in Northland and other locations such as the Bay of Plenty and the South Taranaki Bight. Births of calves could have always been occurring on the main islands' coasts, but were confirmed with two cow-calf pairs in 2012.[191][192]

In the Subantarctic Islands and in the vicinity of Antarctica,[193] where few regulations exist or are enforced, whales can be observed on expedition tours with increasing probability. The Auckland Islands are a specially designated sanctuary for right whales, where whale-watching tourism is prohibited without authorization.[194]

^"Appendix IArchived 11 June 2011 at the Wayback Machine." of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005 and 2008. Effective: 5 March 2009.